perf: use equal byte-by-byte comparison [Google Guava library]

Signed-off-by: Samir Romdhani <samir.romdhani_externe@rte-france.com>

Author: samirromdhani

commons-test/pom.xml

@@ -64,5 +64,9 @@
             <artifactId>slf4j-api</artifactId>
             <scope>compile</scope>
         </dependency>
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+        </dependency>
     </dependencies>
 </project>

commons-test/src/main/java/com/powsybl/commons/test/ComparisonUtils.java

@@ -8,10 +8,9 @@
 package com.powsybl.commons.test;
 
 import com.google.common.io.ByteStreams;
+import org.apache.commons.io.FileUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.xmlunit.builder.DiffBuilder;
-import org.xmlunit.diff.Diff;
 
 import java.io.*;
 import java.nio.charset.StandardCharsets;
@@ -33,12 +32,24 @@ private ComparisonUtils() {
     }
 
     public static void assertXmlEquals(InputStream expected, InputStream actual) {
+        /*
         Diff myDiff = DiffBuilder.compare(expected).withTest(actual).ignoreWhitespace().ignoreComments().build();
         boolean hasDiff = myDiff.hasDifferences();
         if (hasDiff) {
             LOGGER.error("{}", myDiff);
         }
         assertFalse(hasDiff);
+        */
+        try {
+            File expectedFile = new File("expectedFile.xml");
+            FileUtils.copyInputStreamToFile(expected, expectedFile);
+            File actualFile = new File("actualFile.xml");
+            FileUtils.copyInputStreamToFile(actual, actualFile);
+            //Returns true if the files contains the same bytes.
+            com.google.common.io.Files.equal(actualFile, expectedFile);
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
     }
 
     public static void assertTxtEquals(Path expected, Path actual) {